PATHOANATOMY OF INTRAARTICULAR FRACTURES OF THE CALCANEUS

Radiographs of 220 calcaneal fractures (205 patients) were reviewed re trospectively, One hundred and sixty-three fractures were intra-articu lar; thirty (18 per cent) of the 163 fractures were a tongue-type inju ry, and 133 (82 per cent) were a joint-depression injury, Plain radiog raphs and computerized tomography scans in the coronal and axial plane s were available for 116 intra-articular fractures (106 patients), The se studies were reviewed, and the 116 fractures were grouped according to the Sanders classification of calcaneal fractures and the anterior extension of the primary fracture line was evaluated, Sixty-two prima ry fracture lines (53 per cent) extended into one articular surface; t wenty-three (20 per cent), into two articular surfaces; twenty-three ( 20 per cent), into a periarticular location; and eight (7 per cent), i nto a medial or lateral location, Sixty-seven (58 per cent) involved t he calcaneocuboid joint, thirty-one (27 per cent) involved the anterio r facet of the talocalcaneal joint, and ten (9 per cent) involved the middle facet of the talocalcaneal joint, A distinct anterolateral frag ment was identified in 108 fractures (93 per cent), Plain radiographs failed to demonstrate the anterior extension of fifty-one (47 per cent ) of the primary fracture lines, The prevalence of involvement of the anterior facet was significantly greater in Sanders type-III fractures (sixteen of thirty-five; 46 per cent) than in the other types (p < 0. 01), The prevalence of involvement of the calcaneocuboid joint and the middle facet was evenly distributed among the fracture types, The pri mary fracture line typically extends anterior to the angle of Gissane, creating a relatively consistent anterolateral fracture fragment, The primary fracture line cannot be reliably seen on plain radiographs an d is better visualized on computerized tomographic scans.